Tuyere and supporting means therefor



Aug. 30, 1932.

OOIOOOOOO o. NYGAARD 1: ,-1874,340

TUYERE AND SUPPORTING MEANS THEREFOR Filed .Ian. 11, 1950 4 Sheets-Sheet 1 0 OOO IN VEN TOR Aug. 30, 1932. Q [{YGAARD 1,874,340

' TUYIERE AND SUPBORTING MEANS THEREFOR Filed Jan. 11, 1930 4 Sheets-Sheet 2 20 Fig.2 2 15 20 1;-

7 v "prom 0; NYGAARD AND SUPPORTING MEANS THEREFOR Aug. 30, 1932.

TUYERE Filed Jan. 11, 1950 4 Sheets-Sheet INVENTOR BY I 1932- o. NYGAARD 1,874,340

' TUYEHE AND SUPPORTING MEANS THEREFOR Filed Jan. 11, 1930 4 Sheets-Sheet 4 Patented Aug. 30, 1932 UNITEDSTATIES PATENT OFFICE P OSCAR NYGAARD, or serious, MASSACHUSETTS,

AssreNoR 'ro BERNITZ FURNACE AP- PLIANCE COMPANYQOFBOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS 'ruvnnn AND. SUPPORTING MnANs THEREFOR Application filed January 11', 1930. semi no. 420.142.

ing furnaces 'of this type and this fact imposes certain limitations or restrictions on the IQSUltS'WhICh can be obtained from these furnaces. This condition has been further aggravated by the use of preheated airwhich has become a common practice in recent years. Even when operated with due care the tuyeres disintegrate or wear out after a'short time and it is usually necessary to renew them at relatively frequent intervals.

The present invention deals with these conditions and it aims to improve the construction both of tuyeres and of furnaces in which tuyeres are used,'with'a view to minimizing these objections. *The nature of the invention will be readily understood from'the following description when read in connection withthe accompanying drawings, and the novel'features will be particularly pointed out in the appended claims. f 1

In the drawings,

F igurel is a vertical sectional view, partly in elevation, of a furnace embodying features of this invention; v V

Figs. 2 and 3 are plan and sideviews, re spectively, showing individual tuyeres and the means for supporting them in the furnace;

Fig. 4 is a perspective view'cf the bracket construction for supportingthe tuyres,

Figs. 5 and6 are perspective views of a tuyere embodying features of this invention;

Figs. and 8 are plan and side views of another form" of tuyre constructed in accordance with this invention; and

Figs. 9' and 107are plan and side views, re-

spectively, of a top platewhich is used atthe upper ends of the, rows of 'tuyeres shown in Taylor stoker. inclined retortsv 1 shows the inventionembodied in a furnace which for purposes of disclosure has been shown equipped with the well known This furnace has the; usual or fuel channels alternating with rows of tuyeres, one row of tuyeres being shown at 2, the tuyeres and'retorts cooperating to support the fuel bed. The coal hopper of the stoker mechanism is shown at 3,

the ram at 4, and the front, side and rear furnace walls at 5, 6'and 7,- res'pectively. Air under pressure is forcedinto the chamberS immediately below the fuel bed sup ort,1 as is usual in furnaces of this type, an is discharged through the tuyeres into the-fuel bed.

In fact, the entire organization may beof the same general nature as that of the ordinary stoker furnace except for certain features which will be describedmoreparticularly I hereinafter.

An important feature of'this invention resides in the construction and mounting of the tu eres.

hereto ore to make tuyeresf of non-metallic materials which are more highly refractory from that of the iron supports on which it' must be mounted, and unless provision is made foraccommodatlng such expansion and contraction the tuyeres will be broken.

This invention deals especially with these problems.

While it has been proposed.

Referring more particularly toFigs. 6,

inclusive, which illustrate one form of. tuyere embodyingthis. invention, it will be observed that the tuyere there shown comprises a plate& like bottom portion 10, the lower surface of which preferably is. substantially flat. A series of lugs 12 project'from the upper side of this member 10, these lugs being separated from each other by grooves 13. The grooves lead out of and radiate from a chamber 14 formed in the upper side of the tuyere. Both the top and bottom surfaces of the tuyere are substantially flat so that one tuyere'will set on another in overlapping relationship as shown in Figs. 2 and 3, the rearward end of the upper tuyere coming approximately to the rearward end of the 'flat upper surface of the lower tuyere. Lying rearwardly of this flat surface is what may be regarded as the nose portion 15 of the tuyere, to distinguish it from the body part which lies forwardly of the tapered nose. It will be clear from'an inspection of Figs. 2, 3' and 5 that this'nose portion, as shown, has a rounded outline and that it is tapered longitudinally and rounded laterally. This formation is of advantage in enabling the-tuyere to shed the coal and ash, or in other words, to prevent these materials from loadingup the upper surfaces of the tuyeres and tending to obstruct .the flow of air.

As shown in Fig. 2 each tuyere spans the air channel 16 lying between the adjacent air channel walls or retort walls 1717. When the tuyeres are located in their normal overlapping relationship, as shown in Figs. 2 and 3', the air chamber 14 will'be in free communication with the chamber 8, Fig. 1, in which a slight positive air pressure is constantly maintained when the furnace is in operation. Since the grooves 13 radiate from this chamber 14, they conduct an ample supply of air into the fuel bed. Some of these, grooves extend forward and open on to the tapered surface of the'nose 15 while others aredirected laterally and open at the sides of the tuyere. By making the tuyere'very much thicker than the ordinary cast iron tuyere, it can be made from silicon carbide, carborundum, or other refractory non-metallic material and still have ample mechanical strength, while at the same time afiording plenty of cross-sectional area for the grooves so that an abundant supply of air can be discharged into the fuel bed. Preferablythe inner ends ofthe lugs 12 are each tapered to an edge, as clearly shown in the drawings, so as to reducetheir resistance to the flow of air, and the grooves 13 between adjacent lugs grow narrower for a short distance as they extend away from the chamber l4'and then gradually become wider to provide addit'onal cross-sectional area for the air as it expands.

For the purpose of supporting the tuyeres in their operative positions, brackets 2O, Figs. 2, 3 and 4, are secured to thechannel walls 17, each bracket having a groove in the outer side thereof to fit over the upper edge of its'respectivechannel wall. The channels are providedwith lugs 21 cast on. them and-each bracket has-acorrespondinglug 22to rest on the respective lugs 21, the two lugs be ng secured together by a bolt 23. Preferably each lug 22 is slotted to receive the bolt so that the bracket may be adjusted relatively to the channel wall. The brackets are arranged in pairs, the two members of each pair being located in alinement with each other on opposite sides of an air channel 16. In the particular construction shown each bracket has four steps and each pair of brackets is designed to support two tuyeres.

In orderto hold the tuyeres against any substantial movement in a horizontal plane, each bracket is provided with two inwardly extending lugs 2-l2 1', Fig. 4, and each tuyere is notched or recessed at the opposite edges of its heel portion, as shown at 25, Fig. 6, to receive one pair of lugs. It will be clear from an inspection of Figs. 4: and 6 that the heel portion of the tuyere shown in the latter figure can be placed on the two steps Z)Z) of the brackets 2020, Fig. 4, by lowerin this tuyere vertically onto these steps and guiding the lugs 2124: into the two notches 2525 in the heel portion of the tuyere. The extreme forward or left-hand end of the plate portion 10 of the tuyere will fit between the steps 00, and the shoulders 2626 will rest on these steps, the upper surface of the tuyere being substantially flush with the top steps dd. A lower tuyere is similarly supported partly on the steps aa and partly on the body portion of the tuyere immediately below it, and is held against substantial movement out of this position in a horizontal plane by the lugs 21'-24 entered in the sockets 2525 of its respective tuyere. The lugs fit loosely in the recesses and a suitable clearance is provided between the heel end of the tuyere and the brackets so that each tuyere is free to expand and contract relatively to its supporting means, while at the same time being held against any substantial movement away from its operative position. The tuyeres can simply be dropped into their operative positions or lifted out of them.

In some cases it may be desirable to use a centering pin such as that shown at 27, Fig. 3, to enter sockets 28 and 29, Figs. 5 and 6, in overlapping tuyeres. If such a pin is used it preferably is made of silicon carbide or other refractory. non-metallic material. In most constructions, however, such a pin is not required.

A somewhat different embodiment of the invention is shown in Figs. 7 and 8. The tuyeres-shown in these figures are substantially like those shown in Figs. 2, 3, 5 and 6 except that the former constructions are each provided with a second series of lugs 30 located at the lower side of the plate-like member 10. These lugs are separated by air conducting grooves 31. It will be clear from an inspection of Figs. 7 and 8 that the lower lugs 30 are so spaced and arranged that when one tuyere is overlapped upon another in normal 7 relationship the lower lugs of the upper tuyere will register with'the upper lugsof the lower tuyere. Consequently, the grooves 31- between the lower lugs will register with the grooves 13 between the upper lugs.. This construction ispreferred where it is desired to make the tuyere of substantially greater thickness than those shown in Figs. 5. and 6. In this arrangement, also, the grooves 31 radiate from a central air chamber in the lower side of the tuyere in the samegeneral manner that the grooves 13radiate from the chamber 14.v j I I I At theupper end of each line of tuyeres, such as that shown in Fig. 1, a cap plate may be used constructed as shown at 32, Figs. 1, 9 and 10. This cap has a socket 33 to receive a pin like the pin 27, Fig. 3, to hold the cap in alinement with the tuyere immediately below it, and its heel endis reduced in thickness to lit between the walls of the air channel.- Preferably, also, it is provided with a socket or slot 34: to receive a key 35, Fig. 1, projecting from the lower side of "a metal plate 36 which may be held between the retort walls and assists in holding the cap 32 in its opera tive position. v

The tuyere provided by this invention has been found to satisfy the practical requirements for a device of this character. It is sufficiently sturdy and substantial in construction to withstand the rough usage to which these devices are subjected, and because it is more highly refractory than iron it avoids tie objectionable features of tuveres of the common constructions. In addition, the tuyere provided by this invention permits the location of the nose farther forward in the fuel bed whereit can deliver a part of the air deeper into the bed than has beenpossible. with iron tuyeres due to the liability of the latter tuyeres to burn out or melt down under these conditions. These tuyer'es can readily be molded from silicon carbide or other refractory materials, and because oftheir pee culiar design do not require the use of cores. I It is preferable to make the plate-like bottom 10 at least an inch in thickness. In a typical construction this plate is madeone and one-half inches thick and the overall thickness of the tuyere is made approximately three inches, these tuyeres thus being very much larger than theordinary iron tuyere. While this overall thickness could be reduced somewhat, I prefer to use a thickness of at least two inches and I consider it a much better practice to increase this thickness quite substantially. On the other hand, the thickness of the plate-like bottom 10 should not run over three inches and the overall thickness should not be more than six inches.

While I have herein shown and described preferred embodiments of my invention, it will be understood that the invention may be embodiedin other forms without departs ing'IfrOm the spirit or scope thereof.

avin thus described my invention, what I esire to claim as new is:

.1. .In a stoker furnace, the combination of an inclined fuel bed support including an inclined channel for-conducting air to the fuel bed, and a series of refractory nonmetallic tuyeres overlapping each other and covering the top of said air channel for a substantial portion .of its length, each tuyere spanning said channel and having a body portion recessed on its upper side and cooperating :with the tuyere next above it to form an air chamber, each tuyere being provided: also with a nose portion projecting from said body part and extending rearwardly beyond the rear end of the tuyere next: above it, each tuyere also having grooves leading from said chamber through the upper sideof said body part and opening on to the upper surface of said nose.

2. In a stoker furnace, the combination of an inclined fuel bed support including an inclined channel for conducting air to the fuel bed, a series of refractory non-metallic tuyeres overlapping each other and'covering the top of said air channel for a substantial portionof its length, brackets carried by the walls of said air channel and supporting said tuyeres, said tuyeres and brack ets having cooperating parts for loosel holding the tuyeres in their operative positions but permitting them toexpand and contract; I

Y 3. Ina stoker furnace, the combination of an inclined fuel bed support including an inclinedchannelfor conducting air to the fuel bed, a series of refractory non-metallic tuyeres overlapping each other and covering the top of said air channel for asubstantial portion of its length, brackets carried by the walls of said air channel andpro vided with steps on which saidtuyeres are supported in their operative positions, said brackets having lugs and said tuyeresbeing recessed to loosely receive said lugs, whereby thev tuyeres are held by said lugs and brackets intheir operative positions and are permitted to expand and contract under changes in temperature.

A In a stoker furnace,the combination of an inclined fuel bed support including an inclined; channel for conducting air to the fuel bed, a series of refractory non-metallic tuyeres overlapping each other and covering the top ofsaidflair channelfor a substantial portion of its length, brackets carried by thewalls of said air'channel and provided with steps on which said tuyeres are supported in their operative positions, each of said tuyeres including a nose portion to project: into the fuel bed and a heel portion resting on said brackets, groovesin the upper surfaces of said tuyeres extending forward'into jsaid nose-portions and servingito discharge air into the fuel bed, said heel portions having recesses in opposite edges thereof and said brackets having lugs to enter said recesses and hold the tuyeres loosely against movement out of their operative positions in a horizontal plane but permitting the tuyeres to be moved upwardly out of said positions. \5. A tuyere of refractory non-metallic material comprising a body portion having a relatively large recess in the upper side thereof, a rounded'nose extending rearwardlyfrom said body portion and having a rounded and tapered upper surface, and grooves in the upper side of said tuyere leading from said recess to the tapered upper surface of said nose.

6. A tuyere of refractory non-metallic material comprising a body portion having a relatively large recess in the upper side thereof, a rounded nose extending rearwardly from said body portion and having a rounded and tapered upper surface, and grooves in the upper side of said-tuyere radiating from said recess with lugs separating adjacent grooves, said body part having a fiat upper surface formed partly on said lugs to support the heel portion of another tuyere.

7L A tuyre of refractory non-metallic maw terial comprising a body'portion having a FGI . at the ducting grooves relatively large recess in the upper side thereof, a rounded nose extending rearwardly from said body portion and having a rounded and tapered upper surface, grooves in the upper side of said tuyere leading from said recess to the. tapered upper surface of said nose,

and" recesses in the sides of the heel portion of the tuyere for receiving devices for holding the tuyere in its operative position.

8. A tuyere of refractory, non-metallic material comprising a fiat plate-like member extending substantially from end to end of the tuyere and having lugs integral therewith and projecting from one side thereof with grooves separating'said lugs and serving to conduct air to the rearward end of the tuyere, said tuyere having a recess in the upper side thereof into which said grooves open at their forward ends, and a relatively thick nose at the rear end' of the tuyere, said nose being formed on and integral with said plate and being tapered longitudinally and rounded laterally. I I

9. A tuyere of refractory non-metallic material comprising a plate-like member extending substantially from end to end of the tuyere and having two series of lugs extending therefrom, one series at the upper and one lower side of the plate with air conseparating adjacent lugs, the lower series of lugs lying chiefly at the rear of the upper series.

v 10. A tuyere of refractory non-metallic material comprising a plate-like member extending substantially from end to end of the tuyere and having two series of lugs extending therefrom, one series at the upper and one at the lower side of the plate with air conducting groovesseparating adjacent lugs, and a tapered nose integralwith said lugs and plate and having sloping upper surfaces, the lower lugs lying chiefly under said surfaces and the upper lugs lying chiefly in front of said surfaces.

11. A tuyere of refractory non-metallic material comprising a flat plate-like member extending substantially from end toend of the tuyere and having two series of lugs extending therefrom, one series at the upper and one at the lower side of the plate with air conducting grooves separating adjacent lugs, said tuyere having fiat upper and lower surfaces to engage additional tuyeres located respectively, above and below it, and said lower series of lugs being offset rearwardly with reference to said upper series of lugs.

12. A tuyere of refractory non-metallic material comprising a plate-like member extending substantially from end to end of the tuyere and having two series of lugs extending therefrom, one series at the upper and one at the lower side of the plate with air conducting grooves separating adjacent lugs, and a tapered nose integral with said lugs and plate and having sloping upper surfaces, the lower lugs being spaced and arranged to rest on and register with the upper lugs of another tuyere of the same construction, with.

the nose of the lower tuyere projecting beyond the end of the nose of the upper tuyere.

13. A tuyere of refractory non-metallic material comprising a plate-like member extending substantially from end to end of the tuyere and having two series of lugs extending therefrom, one series at the upper and one at the lower side of the plate with air conducting grooves separating adjacent lugs, and a tapered nose integral with said lugs and plate and having sloping upper surfaces,

recesses in both the upper and lower sides of the tuyere from which the grooves at the opposite sides, respectively, of the tuyre radiate, certain of said upper grooves opening on to the sloping surface of said nose, and the lower grooveslying chiefly under said sloping surface.

' OSCAR NYGAARD. 

